Burner assembly producing radiant heat



Aug. 23, 1966 R, D, REED ETAL 3,267,984

BURNER ASSEMBLY PRODUCING RADIANT HEAT Filed Nov. 12, 1964 2Sheets-Sheet 1 INVENTORS ROBERT D. H RSHEL GOOD/V JOHN SMITI-l ZINK Bab;

ATTORNEY United States Patent 3,267,984 BURNER ASSEMFBLY PRGDUQHNGRADlANT HEAT Robert D. Reed, Hershel Goodnight, and dohn Smith Zinir,all of Tulsa, Okla, assignors to John Zinlr Company, Tulsa, Girls", acorporation of Delaware Filed Nov. 12, 1964, Ser. No. 410,375 4(Jlainis. (Cl. 1581.5)

The present invention relates to a burner assembly for the combustion ofliquid fuel or gaseous fuel wherein a burner head unit is arranged insuch relationship with respect to a shaped ceramic structure that thefuel burns and spreads along an annular'surface of the ceramic structureand provides a source of heat which radiates from a large area of therefractory structure.

An object of the invention is to provide a burner assembly adapted forthe combustion of liquid fuel or a gaseous fuel mixture including meansinducing the burning fuel to move along the surface of a ceramicstructure surrounding the combustion zone whereby the burning fuelclings to the ceramic surface and minimizes or substantially eliminatesprojection of flames of burning fuel away from ceramic surfaces of theassembly.

A more detailed object of the invention is to provide a burner structurewherein the major portion of an air supply is directed into the burnerassembly in such a manner as to set up a spinning mass of air into whichthe burning fuel is drawn by the low pressure developed in the whirlingair to thereby promote movement of the burning fuel in a circumferentialpath along the surface of a ceramic member which forms a component ofthe burner assembly.

Other objects and features of the invention will be appreciated andbecome apparent to those skilled in the art to which the inventionpertains as the present disclosure proceeds and upon consideration ofthe accompanying drawings taken in conjunction with the followingdetailed description wherein an embodiment of the invention isdisclosed.

In the drawings:

FIG. 1 is a vertical elevation-a1 view of the forward end of the burnerassembly mounted in a refractory wall.

H6. 2 is a sectional view taken on the line 22 of FIG. 1.

FIG. 3 is a sectional view on a larger scale and taken on the line 3-3of FIG. 1.

FIG. 4 is a fragmentary sectional view of two walls of a heating chambershowing a plurality of the burner assemblies in relation to liquidcarrying tubes.

FIG. 5 is a sectional view taken on the line 55 of FIG. 3.

The present invention pertains to a burner assembly which has utilityfor supplying heat to the exterior of tubes which carry fluids orliquids such as employed in the process industries and the heat suppliedthereto is for conversion of the fluid to the required products. Whileheat generating equipment is known for supplying heat to water tubes orthe like the burner assembly of the present application is designed todrive ultimate quantities of heat through the walls of each increment ofsuch fluids carrying tubes and the quantity of heat supplied is inexcess of that provided by prior equipment and without the flame of theburning fuel playing on or engaging exterior surfaces of such tubes tothereby avoid deterioration of the fluid carrying conduits. A burnerassembly embodying the invention develops radiant heat over a large areaof its refractory components and has utility for purposes in addition todelivering heat to fluid carrying tubes.

Referring to the drawings and to FIG. 1 there is shown at a wall formedof refractory material in which a generally rectangular shaped tilemember 11 formed of ceramic material is mounted. The tile member 11 mayhave a thickness substantially equal to that of the wall 10 as shown inFIG. 4. The outer face of the tile member ll may be covered with sheetmetal as indicated at 12 in FIG. 3. An openng 14 extends through thecentral portion of the ceramic member 11 and this opening iscylindric-ally shaped throughout more than one-half the thickness of theWall structure. The opening 14 flares outwardly from the end 16 of thecylindrical portion of the opening 14. The outwardly flared surface 17is also of arcuate convex shape when viewed in section and this arcuatesurface merges flush with the inner face 18 of the tile member 11 andwhich is desirably in the same plane as the inner face 19 of the wallll).

The burner assembly includes a generally cylindrical housing member 21which is accommodated within the cylindrical shaped portion of theopening 14 as shown in FIG. 3. A flange 22 carried by the housing member21 overlies the outer face of the wall 10 around the mouth of theopening 14 and provides means for supporting the burner assembly on therefractory structure. An annular element 23 is mounted within thehousing member 21 and has a frusto-conical shaped intermediate portion24 which flares outwardly in proceeding downstream of the burnerassembly. A cylindrical shaped sleeve 26 is carried by the largerdiameter end of the frusto-conical shaped portion 24. An annular rib 27projects radially from the element 23 and this rib may be attached tothe housing member 21 in any suitable manner such as by welding asindicated at 28. The small diameter end portion of frusto-conicalportion of the element 23 provides a throat 25 for accommodating theforward end of a burner head unit. A cup-shaped upstream end portion ofthe element 23 includes a cylindrical shaped annular wall 31 as shownin? FIG. 3 of materially larger diameter than the throat 2.).

A conduit 32 extends into the upstream end of the housing 21 as shown inFIG. 3. Air is admitted to the conduit 32 through a laterally disposedfitting 33 depicted Ill]. FIG. 2. An annular wall 34 closes the upstreamend of the housing 21 with respect to the perimeter of the conduit 32.The conduit 32 desirably has substanially the same external diameter asthe annular wall 31 of the element 23 and the conduit 32 may be securedthereto in any suitable manner such as by welding indicated at 36.

A burner head unit indicated generally at 38 extends into the throat 25.The burner head for gaseous fuel is formed by a guide tube 39 and asleeve 41 which surrounds the guide tube 39 in spaced relationship andprovides an annular space 42 between the guide tube 39 and the sleeve41. This burner head is supported within the annular element 23 by meansof a plurality of radially disposed lugs 43 which are carried by acollar 44 which surrounds the sleeve 41. The outer ends of the lugs 43engage the inner surface of the annular wall 31. A plurality ofdischarge ports 46 are arranged in a circular row at the downstream endof the burner head for gaseous fuel. The exterior of the sleeve 41 isspaced from the throat 25 to provide an annular passage for air to moveover the exterior of the burner head unit. A baffle 47 is carried by thesleeve 41 adjacent the downstream end thereof and near the dischargeports 45 to restrict the area of the annular passage within the throat25.

A pipe 51 is attached to the upstream end of the sleeve 41 and extendsbeyond the outer end of the conduit 32. A gaseous fuel mixture issupplied into the pipe 51 through a conduit fiting 52 shown in FIG. 2.The guide tube 39 extends outwardly and upstream beyond the end of thepipe 51. The gaseous fuel mixture supplied into the pipe 51 movesthrough the annular passage 54 provided between the interior of the pipe51 and the exterior of the guide tube 39 and into the annular passage 42for escape through the discharge ports 46. The burner head unit includesa nozzle 56 for liquid fuel and this burner tip is accommodated withinthe guide tube 39. The forward end of the nozzle 56 is provided withdischarge apertures 57 for discharging liquid fuel as small dropletsdownsream from the nozzle 56 in a substantially conical pattern. Theliquid fuel is supplied to the burner tip through a pipe 58.

A plurality of openings 61 are provided through the Wall of the conduit32 whereby a major portion of the air admitted through the fitting 33escapes outwardly through the openings 61 as indicated by the arrows 62into the plenum 63 formed exteriorly of the element 23 with this airconfined therein by the housing member 21. A plurality of apertures 64extend through the frustoconical portion 24 of the element 23 near therib 27. The apertures 64 have their axes disposed tangentially withrespect to the cylindrical sleeve 26 and all of these apertures slope inthe same direction in proceeding in one direction circumferentially ofthe assembly. A minor portion of the air admitted into the conduit 32moves in the direction of the arrows 66 and through the throat 25 andover the downstream end of the burner head unit 38.

In operation and when liquid fuel is to be burned such fuel is suppliedinto the pipe 58 at relatively high pressures. The liquid is dischargedthrough the apertures 57 as tiny droplets and in a conical pattern asrepresented by phantom lines in FIG. 3. Air at relatively high pressuresis supplied through the conduit fitting 33 and this air moves into thecombustion zone in two separate paths. The major portion of the airflows from the annular space 68 through the openings into the plenum 63and thence through the tangentially disposed apertures 64. The apertures64 are designed to provide a maximum pressure drop across each apertureso that the air attains a maximum velocity in passing through theapertures 64. The high velocity of this air develops a rapidly spinningmass of air within the cylindrical sleeve 26 to create a substantiallydough-nut shaped mass of whirling air in an annular pattern as indicatedat '71. A minor portion of the air in the annular space 68 moves in thedirection of the arrows 66 and flows through the throat 25 over theperiphery of the burner unit and over the perimeter of the baffle 47.There is no circumferential component imparted to this air and it doesnot spin. This portion of the air controls the zone at which thedroplets of liquid fuel are subjected to the action of the violentlyspinning air mass 71. The quantity of air moving through the throat 25may vary from five to ten percent of the total air quantity.

The pressure within the whirling air mass 71 is extremely low and theliquid fuel droplets are drawn into this violently spinning air. Theturbulence and violence of the whirling air breaks the droplets ofliquid fuel into smaller droplets of micron size and which are so smallthat the fuel particles then appear as smoke which burn with extremerapidity. Initial ignition of the liquid fuel may be established in anyconventional manner and combustion of the liquid fuel is maintained bythe return of the hot gases as represented by the arrows 72 to elevatethe liquid fuel to a temperature where stable auto-ignition ismaintained. The spining fuel undergoing combustion burns with a brightblue color near the free end of the cylindrical sleeve 26. An annularshaped ceramic member 76 is provided within the housing 21 adjacent thedownstream end of the sleeve 26. The inner annular surface 77 of theceramic member 76 flares outwardly in proceeding downstream of theburner assembly and de sirably has curvature which merges smoothly withthe arcuate surface 17 forming .the exit end of the opening in the tilemember 11.

The flame developed in the spinning air mass 71 moves circumferentiallyof the assembly at a rapid rate. The pressure within this burning massis low and the burning fuel and gases spin against the inner surface 77of the ceramic member 76. This surface is solid and the low pressurewithin the burning fuel causes the burning fuel to cling to the surface77 and cling to the surface 1.7 of the tile member 11. Centrifugal forceurges the burning fuel against the surface 17 so that the flame clingstightly to the surface 77 and to the surface 17. The burning fuel movesalong these arcuate ceramic surfaces and there is virtually noprojection of the flame away from these arcuate surfaces. The downstreamface 18 of the tile member 11 and the downstream face 19 of the wall 10are scrubbed with heat. Heat is transferred to the tubes 79 (FIG. 4) asenergy radiating from the wall it) and the tile member if. The flamedoes not play upon the external surfaces of the tubes 79.

The gaseous fuel mixture is supplied into the pipe 51 through thefitting 5'2 and the gaseous fuel mixture moves into the annular space 54and escapes through the discharge ports 46 in the burner head unit. Thepressure at which the gaseous fuel is supplied is controlled so as toprovide for a suitable quantity of the gaseous fuel mixture to flow fromthe discharge ports 46 in a frustoconical pattern along the innersurface of frusto-conical portion 24 of the element 23 and into thespinning air mass 71. The air entering through the throat 25 mixes withthe gaseous fuel. This fuel burns stably after ignition an suitablecombustion is established by the time the burning gaseous fuel mixturearrives in the presence of the whirling air mass 71. The burning gaseousfuel moves along the inner surfaces of the ceramic member 76 and thetile member 11 in a manner similar to that described in connection withthe burning liquid fuel.

While the invention has been described with reference to a particularburner assembly it will be appreciated that changes may be made in theelements as well as the overall combination. Such changes andmodifications along with others may be made without departing from thespirit and scope of the invention as set forth in the appended claims.What we claim and desire to secure by Letters Patent 1. In a burnerassembly for producing radiant heat, a refractory wall, a ceramic tilemember mounted in said wall with the inner face thereof flush with theinner face of said wall, said tile member having an opening through thecentral portion thereof, a flared annular surface defining the exit endof said opening, said flared annular surface being of convex shape insection and merging smoothly with the inner face of side wall, a housingmember within said opening, an annular element within said housingmember having a throat of smaller cross section than other portions ofsaid annular element, a burner head unit mounted with-in said throat,means for supplying fuel into said burner head unit for discharge in aflaring [pattern into the downstream end portion of said annularelement, means guiding air over the exterior of said burner head unitand through said throat into the presence of the fuel discharged fromthe burner head unit to support combustion of the fuel, said annularelement having a plurality of 'circumtferentially spaced aperturestherethrough downstream of said burner head unit arranged generallytangentially of the annular element with the axes of all of saidapertures sloping in the same direction in proceeding circumferentiallyof said annular element, means guiding air at pressures aboveatmospheric through said apertures, said aperture-s producing pressuredrop in the air passing the-rethrough and directing the air in acircumferential swirl as a consequence of the tangentially dispositionof the apertures whereby the burning fuel is drawn into the swirling airso that the burning fuel moves along said flared surface Withoutdevelopment of flames of any substantial extent away from said flaredsurface.

2. In a burner assembly for producing radiant heat, a refractory wall, aceramic tile member mounted in said wall with the inner face thereofflush with the inner face of said wall, said tile member having anopening through the central portion thereof, an annular surface flaringoutwardly from the axis of said opening and merging smoothly with theinner face of said wall, a housing member within said opening, anannular element within said housing member providing an annular plenumbetween said housing member and said annular element, said annularelement having a throat of smaller cross section than other portions ofsaid annular element, a burner head unit mounted within said throat,means for supplying fuel into said burner head unit for discharge in aflaring pattern into the downstream end portion of said annular element,means guiding air over the exterior of said burner head unit and intothe presence of the fuel discharged from the burner head unit to supportcombustion of the fuel, means supplying air into said plenum atpressures above atmospheric, said annular element having a plurality ofcircumferentially spaced apertures the-rethrough and located downstreamfrom said burner head unit, said apertures being arranged generallytangentially of the annular element with the axes of all of saidaperture-s sloping in the same direction in proceeding circumferentiallyof said annular element, said apertures producirrg pressure drop in theair passing therethrough and directing the entering air in a circularpath along the inner surface of said annular element with the burningfuel drawn into the swirling air whereby the burning fuel moves aroundand along said flared surface without development of flames of anysubstantial extent away from said flared surface.

3. In a burner assembly according to claim 2 wherein the annular elementin the portion between the burner head unit and said apertures has afirusto-conical shaped inner surface.

4. In a burner assembly according to claim 2 wherein a ceramic memberwithin the downstream end of said housing member has an annular surfacewhich fiares outwardly from the axis of the housing. member and guidesthe burning fuel onto the surface of said tile member.

References Cited by the Examiner UNITED STATES PATENTS 2,527,503 10/1950Sinclair et al. 158-l.5l 2,969,833 1/1961 Bloom et al. 15811 3,133,7315/1964 Reed 158-11 X 3,203,462 8/1965 Prowse 1581.5

FREDERICK L. MATTESON, JR., Primary Examiner.

E. G. FAVORS, Assistant Examiner.

1. IN A BURNER ASSEMBLY FOR PRODUCING RADIANT HEAT, A REFRACTORY WALL, ACERAMIC TILE MEMBER MOUNTED IN SAID WALL WITH THE INNER FACE THEREOFFLUSH WITH THE INNER FACE OF SAID WALL, SAID TILE MEMBER HAVING ANOPENING THROUGH THE CENTRAL PORTION THEREOF, A FLARED ANNULAR SURFACEDEFINING THE EXIT END OF SAID OPENING, SAID FLARED ANNULAR SURFACE BEINGOF CONVEX SHAPE IN SECTION AND MERGING SMOOTHLY WITH THE INNER FACE OFSIDE WALL, A HOUSING MEMBER WITHIN SAID OPENING, AN ANNULAR ELEMENTWITHIN SAID HOUSING MEMBER HAVING A THROAT OF SMALLER CROSS SECTION THANOTHER PORTIONS OF SAID ANNULAR ELEMENT, A BURNER HEAD UNIT MOUNTEDWITHIN SAID THROAT, MEANS FOR SUPPLYING FUEL INTO SAID BURNER HEAD UNITFOR DISCHARGE IN A FLARING PATTERN INTO THE DOWNSTREAM END PORTION OFSAID ANNULAR ELEMENT, MEANS GUIDING AIR OVER THE EXTERIOR OF SAID BURNERHEAD UNIT AND THROUGH SAID THROAT INTO THE PRESENCE OF THE FUELDISCHARGED FROM THE BURNER HEAD UNIT TO SUPPORT COMBUSTION OF THE FUEL,SAID ANNULAR ELEMENT HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACEDAPERTURES THERETHROUGH DOWNSTREAM OF SAID BURNER HEAD UNIT ARRANGEDGENERALLY TANGENTIALLY OF THE ANNULAR ELEMENT WITH THE AXES OF ALL OFSAID APERTURES SLOPING IN THE SAME DIRECTION IN PROCEEDINGCIRCUMFERENTIALLY OF SAID ANNULAR ELEMENT, MEANS GUIDING AIR ATPRESSURES ABOVE ATMOSPHERIC THROUGH SAID APERTURES, SAID APERTURESPRODUCING PRESSURE DROP IN THE AIR PASSING THERETHROUGH AND DIRECTINGTHE AIR IN A CIRCUMFERENTIAL SWIRL AS A CONSEQUENCE OF THE TANGENTIALLYDISPOSITION OF THE APERTURES WHEREBY THE BURNING FUEL IS DRAWN INTO THESWIRLING AIR SO THAT THE BURNING FUEL MOVES ALONG SAID FLARED SURFACEWITHOUT DEVELOPMENT OF FLAMES OF ANY SUBSTANTIAL EXTENT AWAY FROM SAIDFLARED SURFACE.